Thats exploding transformer station was kool to see :D

http://205.243.100.155/frames/longarc.htm#Blowup

Hi all,
I decide to look into the option to install my 4221/4228 on the roof, I have a few questions before I jump. Hope all your pros can help me out here.

1) how you bring your equipment, Tripod and cm 4228/4221 to the roof.

2) my attic has the built-in pipe line to the basement, How may I bring the cable into the attic without cause the leaking.
I used a rope to pull all the stuff up to the roof. After i got off the ladder that got me to the roof, i pulled it up as well, to use on the roof and adjust the antenna after it was mounted.

If your roof is steep, i would strongly recommend a travel restraint harness and you should be tied off with a rope that won't let you go over the edge.

I used roofing chaulking to seal all the holes i drilled, under and around all mouning bolts/screws.

For my roof antenna, I ran the cable over the edge of the roof and drilled a hole in the wall to come back into the house.

My satellite dish is on my garage and I drilled 5/16" holes (just big enough for RG-6 cable) for all 4 cables and used chaulking in/around the holes. Haven't had a leak in 6 years.

For my roof antenna, I ran the cable over the edge of the roof and drilled a hole in the wall to come back into the house.

A couple other hints are to drill the hole reasonably close to the peek so that the overhang should protect the hole from the rain. You should also have the cable loop lower than the hole so that water running down the cable will drip off (water won't run up hill).

If you don't have a wall in the attic that you can go through, an alternate would be to go up through the soffits.

I used a rope to pull all the stuff up to the roof.
Also, you can tie off the rope around a plumbing vent stack. This will prevent loosing the rope if anything "slips". I wouldn't recommend tying it off around a roof vent (the ones designed to ventilate the attic space) - they are typically not very secure.

I ran the cable into the attic through one of the plastic roof vents. No need to cut any holes, and it didn't damage the vent at all. Just slightly spread the plastic mesh that prevents birds/animals to enter the attic via the vent.

Well,

Get my 4221 today and just set it up at the place of my original powered RCA rabbit ear in the living room. The result are very disapointed. I lost all my digital channel 5-1 and 9-1. Seems the 4221 is indeed the outdoor antenna. maybe attic isn't an option anymore.
BTW : still have a hard time to find the pipeline from attic to basement. does anyone has any idea where it normally located and what it looks like. I remember I paid for that upgraded feature.

Vincent

Referring to this post:

http://www.digitalhome.ca/forum/showpost.php?p=527322&postcount=218

Stampeder, you being the resident expert on Antennas… do you think he’s installed the 2 antennas too close together? Don’t you need to have around 3 feet between antennas to keep them from interacting with one another?

HDTV101 just wondering why would you require a 3' spacing between a vhf and uhf antenna separate frequency. Maybe combining two of the same type like a pair of uhf or vhf antenna's might require some fine tuning and spacing.

But then again look at the 4228 two 4221 mounted side by side and no 3' spacing.

When you buy any premade channel master vhf/uhf antenna there is no 3' space there.

On the install we hooked up and tried each antenna separately and after combined with a channel master vhf/uhf.

There was no negative or signal loss on any channels.

Get my 4221 today and just set it up at the place of my original powered RCA rabbit ear in the living room. The result are very disapointed. I lost all my digital channel 5-1 and 9-1.

Are you sure you have it pointing in the right direction? For UHF it should be better than any indoor antenna.

BTW : still have a hard time to find the pipeline from attic to basement. does anyone has any idea where it normally located and what it looks like. I remember I paid for that upgraded feature.


No guarantees that the builder actually put it in. That is why it is important to regularly check during construction that everything is as you are expecting.

If it is there, it will probably be a piece of plastic conduit about an inch (or slightly more) in diameter. They could have put it anywhere that the found it convenient, but logic would say that it would be near the service panel on the basement end and directly above in the attic. Alternately they may have put it inside a cold air return. Ask the builder what they usually do. Regardless, it is probably hidden by insulation.

Don’t you need to have around 3 feet between antennas to keep them from interacting with one another?If the antennas are both in the same band (lets say 2 VHF antennas) and not stacked or ganged together (lets say one pointing at channel 2 to the north, the other pointing at channel 5 to the south) the ideal spacing would be one wavelength of the lowest target channel between them on the mast (in this example, a full wavelength of Channel 2).

Unfortunately a Channel 2 VHF (frequency of 54 MHz) wave is 18 feet! That's crazy, so over the many years of TV it has been found that one-quarter wave is just fine, which is about 4 1/2 feet.

If its a VHF and a UHF pair, my rule of thumb has always been to leave at least 1 foot.

Stampeder, you beat me to it although I am not convinced that 1 foot would be adequate. The issue isn't so much that the other antenna is actively generating an interfering signal but that antennas optimally want to be suspended in mid-air, surrounded by nothing. In reality this isn't possible since at a minimum you will have the mast there but I would want to keep the antennas at least a 1/4 wavelength (of the lowest channel you want to receive) apart (1/2 wavelength would be better).

I've just found that 1 foot did the trick as a general rule of thumb for VHF and UHF antennas, but if you have better results with more, that's great and I might change my old habit.

I have to add that for pro uses like CATV head ends, schools, etc., a full wavelength separation is the only way to go, and it would take very strong reasons against doing that (i.e. lack of space) to use a half or quarter wave.

For most consumer roof tops in urban areas a quarter wave should be okay. For deep to deepest fringe use in rural areas a full wave is the way to go.

Stampeder, I am not an expert by any means, but my comments are based my rudimentary knowledge of RF theory. You may not be able to see them, but RF waves are 3 dimensional and interfering with part of the wave can cause it to be distorted. However, if you have done experiments and have found 1 foot is adequate then real life experience trumps theory any day.

I even believe some Ham operators put their secondary UHF antennas on opposite ends of a cross-mounted boom to keep the elements away from the mast. Horizontal vs vertical polarization comes into effect here some place as well, but I know nothing about Amateur Radio Operators. I think that they are even concerned about the placement/orientation of their downlead/cable with respect to the array.

antennas optimally want to be suspended in mid-air
Roger, I'm having an epiphany/vision... Giant mylar weather balloon... 500' of altitude.... several hundred meters of fishing line.... Got to run, I'm off to Rona!!

Roger, I'm having an epiphany/vision... Giant mylar balloon... 500' of altitude.... several hundred meters of fishing line.... Got to run, I'm off to Rona!!

LOL. And how are you going to keep it from blowing in the wind?

Future news report: "99gecko was last seen drifting into North Korean air space beneath a giant weather balloon..."

stampeder no you have the location all wrong. :) 99gecko had been sited as drifting into Iranian airspace and being held by the Iranians along with the british troops.

Are you sure you have it pointing in the right direction? For UHF it should be better than any indoor antenna.Hi,
At the recent couple days , I've tried different locations/ floors/ angles/windows /transfomer inside the house with 100 ft rg6 cable. and so far has no much luck. only got 10% of CBC. every time I connected back to the amped rca rabbit ear i got 51% of CBC (5-1 ).
The question now are:
1) Would it be possible that long cable without amp cause the less signal strench than the rabbit ear (POWERed)?
2) A defective antenna or assembly? ( unlikily, everything seems in good sharp)
3) IS my house built with metal brick?

I know the higer it is better, I just don't want to get up and install it to the roof then find out I have a defective antenna or dead spot for reception. Any pointers that I can test/comfirm it works before I pull all my hairs out.....

Thanks in advance

Vincent

Hi Vincent I already gave you some advise on where the antenna needs to be mounted.

I definately would not expect any decent results using a 4221 indoor or even a attic install with 100' of cable with no preamp.

After playing around with a calculator instead of relying on my gray cells I went back and corrected post #454. :)